The goal of this project is to understand how repeated experience can stably modify a neuron's activity by studying the molecules that affect the nuclear localization of the cGMP-dependent protein kinase EGL-4 during long-term odorant adaptation in C. elegans. This understanding will provide us with insight into mechanisms of learning and memory and molecular processes that underlie addictions. Nuclear localization of EGL-4 in odorant sensory neurons is necessary for the transition from short to long-term adaptation that occurs upon continual stimulation to an odorant. We propose to study the molecules that regulate this nuclear translocation. By utilizing a GFP-tagged EGL-4 molecule to visualize in real-time the behavior of EGL-4, we will examine the localization of EGL-4 in known components of both odorant chemotaxis and adaptation. We will also genetically screen for individuals that are defective in EGL-4 nuclear translocation to identify new components of adaptation that regulate the transition to long-term adaptation. The results from this study will give us a clearer understanding of neuronal plasticity. [unreadable] [unreadable]